Gesture recognition is one of the most sought-after topics of 3D computer vision. Through gesture recognition, humans can communicate nonverbally and interact with machines naturally without any mechanical input device. Thus, a wide variety of applications have been enabled or advanced by the gesture recognition technology, for example, animation production and movie effects, interactive gaming, robotics control, home appliance control, medical device automation, driverless car control, etc. Gestures generally include movements of the hands, face, and/or other body parts. Since humans commonly use hands to express emotions, give commands, or perform other types of communication, 3D hand skeleton tracking, as a method for accurately capturing hand or finger positions, postures, and movements, falls right in the frontier of the technological development. To this end, various hand or hand skeleton tracking models have been developed to simulate human skeletons in real time.